Calendar driving mechanism for date and week day indicating timepiece

ABSTRACT

A driving wheel making one revolution in 24 hours automatically indexes the date indicator and the week day indicator at midnight by means of a date indexing member and a week day indexing member. At a predetermined point of its revolution the driving wheel produces the engagement of a detent mechanism that afterwards progressively bends the two indexing members. At a further predetermined point of its revolution the driving wheel produces releasing of the detent mechanism so that the indexing members become free simultaneously and index the two indicators in unison.

United States Patent [191- Zaugg ]March 20, 1973 [54] CALENDAR DRIVING MECHANISM 1F 0R ATE AND WEEK DAY INDICATING TIMEPIECE [75] Inventor: Roland Zaugg, Grenchen, Switzerland [73] Assignee: A. Schild S.A., Grenchen (Canton of Soleure), Switzerland 22 Filed: Aug. 17, 1971 21 Appl.No.: 172,438

[30] Foreign Application Priority Data Aug. 19, 1970 Switzerland ..1240l/70 [52] U.S. Cl ..58/58 [51] Int. Cl. ..G04b 119/24 [58] Field of Search ..58/4, 5, 58

[56] References Cited UNITED STATES PATENTS 3,527,047 9/1970 Bolle ..58/58 3,413,800 12/1968 DuBois et al Teramoto et al. ..58/58 3,439,493 4/1969 Mutter et al.. ..58/58 3,451,211 6/1969 Nakagawa ..58/58 FOREIGN PATENTS OR APPLICATIONS 425,641 6/1967 Switzerland ..58/58 1,563,142 4/1969 France ..58/58 Primary Examiner-George H. Miller, Jr. AttorneyStevens, Davis, Miller & Mosher [5 7] ABSTRACT A driving wheel making one revolution in 24 hours automatically indexes the date indicator and the week day indicator at midnight by means of a date indexing member and a week day indexing member. At a predetermined point of its revolution the driving wheel produces the engagement of a detent mechanism that afterwards progressively bends the two indexing members. At a further predetermined point of its revolution the driving wheel produces releasing of the detent mechanism so that the indexing members become free simultaneously and index the two indicators in unison.

5 Claims, 2 Drawing Figures PATENTEB MARZO I975 SHEET 10F 2 CALENDAR DRIVING MECHANISM FOR DATE AND WEEK DAY INDICATING TIMEPIECE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the calendar driving mechanisms for date and week day indicating timepieces and, more particularly, to such mechanisms in which the date indicator and the week day indicator are indexed by a driving wheel making one revolution in 24 hours.

2. Description of the Prior Art Calendar mechanisms having a date indicator being instantaneously indexed through one thirty-first of a complete revolution every 24 hours are well known in the art. Calendar mechanisms being adapted for wristwatches and comprising a date indicator and a week day indicator are also well known. With the known watches the week day indicator usually consists of a disc being secured onto a star member and having a diameter smaller than that of the ring carrying the date indications and constituting the date indicator. Now, with most of the calendar watches having date and week day indications, the wheel making one revolution in 24 hours carries a pin which, at a predetermined moment of its revolution around the wheel axis, engages a point of the week day star member and indexes the same. As a matter of fact, the pin of the driving wheel drives the week day star member until one point thereof moves beyond the tip of the spring-pressed detent provided for normally holding the indicator at rest in the correct indicating positions. The week day indicator is then moved farther by this spring-pressed detent until it reaches' the next indicating position in which the spring-pressed detent rests on two points of the star member. Indexing the week day indicator thus occurs in two phases. It is firstly moved progressively, and then it jumps.

The known calendar driving mechanisms of this type have, however, two drawbacks. The first drawback comes from the indexing phase lasting some hours. During that time, the week day indication is, indeed, more or less displaced with respect to the dial window in which it normally appears so that it can no more be read easily or is even not readable any more. The second drawback results from the manufacturing conditions. It has namely been observed that the springpressed detent cooperating with the week day star member can hardly be adjusted relative to the points of the star member in such manner that the week day indicator jumps at the same time as the date indicator in the second indexing phase. Relatively great differences, ranging up to minutes or even half an hour, are thus usual between these jumping times. The date and week day reading is accordingly no more reliable in the period during which indexing of the corresponding indicators takes place.

SUMMARY OF THE INVENTION It is therefore an object of the invention to improve the calendar driving mechanisms of the type considered here in such manner as to avoid the above-mentioned drawbacks.

A more particular object of the invention consists in a calendar mechanism comprising, on the one hand, an indexing member associated with each indicator and being movable from a rest position to a bent position while being permanently urged toward its rest position, and, on the other hand, a detent mechanism becoming engaged in a first predetermined position of the wheel driving the calendar mechanism and being released in a further predetermined position of this driving wheel, the detent mechanism, upon being engaged, causing both indexing members to move from their rest position toward their bent position until the driving wheel reaches the position in which the detent mechanism is released and the indexing members accordingly liberated simultaneously so that they index the two indicators in unisson.

Still further objects of the invention will become apparent in the course of the following description.

BRIEF DESCRIPTION OF THE DRAWINGS One embodiment of the calendar driving mechanism according to the invention is represented diagrammatically and by way of example in the accompanying drawings.

In the drawings:

FIG. 1 is a plan view on the dial side of the movement of a wrist-watch having the improved calendar driving mechanism built in, some pieces being broken away, and

FIG. 2 is a sectional view on a larger scale along line II-II of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT The calendar watch movement represented in the drawings comprises on a baseplate 1 an hour wheel 2 mounted for rotary motion in the center thereof and having a tubular projection encompassing a cannon pinion carrying the minute hand. The hour wheel 2 meshes with a wheel 3 making 1 revolution in 24 hours. A ring shaped date indicator 4 carrying the indications 5 from 1" to 31 on its upper surface extends over a peripheral portion of base-plate 1 and is normally driven in the direction of arrow 6. The date indications 5 successively appear in a window provided in the watch dial (not shown). The date indicator 4 is provided with an inner toothing 7 comprising 31 teeth, as it is usual in the art. Indicator 4 is held in place on baseplate 1 by means of a cut-out plate which is secured to the base-plate 1 and holds in place several members of the mechanism described hereinafter. The watch represented in the drawing moreover comprises a week day indicator comprising a disc 9 having an outer diameter somewhat smaller than the inner diameter of ring 4. A star member 10 is fixed to the back side of disc 9. The seven week day indications 11 are printed radially on the upper surface of disc 9 so as to appear in a second elongated window provided in the watch dial. The week day star member 10 comprises fourteen points. This star member is indexed every day so as to move two points forward as described in detail hereinafter. A detent 12 mounted for rocking motion around a bearing surface of a screw 13 screwed into base-plate 1 is set under the action of a spring blade 14 having one end secured to the detent l2 and the other end bearing in a cut-out 15 provided in the cover-plate 8. Spring 14 urges detent 12 against the week day star member 10. The spring-pressed detent 12 engages two adjacent points of star member thus normally holding star member 10 at rest in predetermined angular positions with respect to base-plate 1, in which the day indications 11 are centered in the corresponding window of the watch dial. The date indicator 4 is similarly held normally in predetermined angular positions of rest by means of a detent 16 being pivotally mounted on a pin 17 and set under the action of a spring 18. The spring-pressed detent l6 and the corresponding spring 18 are held in place by the cover-plate 8. The acting noses of detents 12 and 16 have such a shape as to cooperate with the toothings of the corresponding indicators and to hold the same safely in predetermined angular positions in which the indications carried thereby are centered in the corresponding dial window, the indicators leaving their positions of rest only when they are indexed by the calendar driving mechanism disclosed hereinafter or by a calendar correcting device (not shown).

Ring 4 and disc 9 are indexed once every 24 hours by a driving mechanism substantially comprising a week day indexing member 19 and a date indexing member 20.

The date indexing member is of a type well known in the art. It chiefly comprises a rocking lever 21 constituted by a cut-out plate and being pivotally mounted around a stud 22 fixed to base-plate 1. For that purpose stud 22 extends within an elongated slot 23. Lever 21 is set under the action of a spring 24 and it carries a driving pawl 25 pivotally mounted on lever 21. Pawl 25 is itself set under the action of a spring blade 26 inserted and secured in a slot provided in a thicker end portion 27 of lever 21. Spring 26 normally holds pawl 25 in abutting engagement with a pin 28 fixed to lever 21. In its position of rest represented in the drawings pawl 25 has its driving end entering a gap of toothing 7 of ring 4. When lever 21 rocks clockwise in FIG. 1, pawl 25 rocks against the action of spring 26 so as to jump over the tooth located behind the driving end of pawl 25. This rocking motion of lever 21 bends spring 24, the end of which bears against a projection 29 of lever 21 located between the pivoting axis 22 of this lever and the toothing of the date indicator. Due to that arrangement it appears that lever 21 quickly rocks counterclockwise under the action of spring 24 if it is released after having rocked clockwise. During this counterclockwise rocking motion of lever 21 under the action of spring 24 the driving nose of pawl 25 engages the rear flank of the tooth over which this nose has jumped during the clockwise motion of lever 21. This tooth flank and the nose edge engaging the same are oriented in such a manner that pawl 25 drives the date indicator in the direction of arrow 6 when lever 21 rocks counter-clockwise toward its rest position represented in FIG. 1. During this counter-clockwise motion of lever 21 the rear nose 27 of the latter also enters a tooth gap of the date indicator, thus preventing this indicator from unduly jumping several teeth forward thus warranting a correct indexing of the date indicator.

As regards the week day indexing member l9, it is similarly arranged so as to ensure a quick indexing of the week day star member 10. Member 19 is, moreover, provided so as to control lever 21. It is therefore composed of two parts: a driving finger 30 and a control nose 31. Finger 30 is made integral with a hub portion provided with a central opening. The hub portion of finger 30 moreover comprises a first cylindrical surface 32 (FIG. 2) freely entering the central opening of the driving wheel 3, and a second cylindrical surface 33 on which the part carrying the control nose 31 is set with force fit. The two parts composing member 19 are thus rigidly fixed to each other; they are, moreover, mounted for free rotation relative to wheel 3 which is carried thereby. A screw 34 screwed into base-plate 1 comprises a bearing surface serving as pivot for member 19 and accordingly wheel 3. FIG. 1 shows that the control nose 31 comprises a triangular projection 35 at its periphery and, on the side of this projection, a cut-out 36 extending between two radial flanks of a central hub portion of control nose 31. The peripheral extent of cut-out 36 is chosen so as to ensure a proper operation of the week day indexing member as described hereinafter in detail. The driving wheel 3 is made integral with a projection 37 extending within cut-out 36. This cut-out 36 and projection 37 constitute a claw coupling between member 19 and wheel 3. This coupling has, however, a free play corresponding to the peripheral length of cut-out 36 and allowing a rotary motion of wheel 3 relative to member 19 through a predetermined angle. Member 19 is, moreover, connected to wheel 3 by means of a U- shaped spring blade 38 having one end inserted and secured in a slot provided in the driving finger 30 and the other end anchored to a stud 39 riveted to wheel 3. Spring 38 normally holds member 19 in such a position relative to wheel 3 that projection 37 of this wheel bears against the rear flank limiting cut-out 36 as shown in FIG. 1. In this rest position spring 38 is already slightly bent. Those skilled in the art will understand that if member 19 is retained, for instance, in the position represented in full lines in FIG. 1, the driving wheel 3 will rotate along counter-clockwise, thus causing projection 37 to move along cut-out'36 and spring 38 to be bent progressively.

The operation of the calendar driving mechanism disclosed will now be understood easily. In the position represented in full lines in FIG. 1, projection 35 of the week day indexing member 19 just engages a triangular projection 41 of lever 21 which lies in the path of projection 35. Before having reached that position the week day indexing member 19 and the driving wheel 3 rotated at the same speed in unison, the week day indexing member 19 being held by spring 38 in the position in which the rear flank limiting cut-out 36 bears against projection 37 of wheel 3. Since in the position represented in full lines in FIG. 1 the projection 35 of control nose 31 has just come into abutting engagement with projection 41 of lever 21, member 19 is momentarily prevented from rotating farther together with wheel 3. The latter thus moves on alone thereby progressively bending spring 38 while projection 37 moves within cut-out 36. This operation is possible because spring 38 is substantially weaker than spring 24, which accordingly holds lever 21 in its rest position. When projection 37, however, reaches the other end of cut-out 36 and accordingly engages the fore flank limiting this opening, a rigid connection is established between the driving wheel 3 and the week day indexing member 19. From that moment onwards member 19 again moves together with wheel 3 so that projection 35 of control nose 31 causes lever 21 to rock around stud 22 while bending spring 24. This motion lasts during about one to two hours. During that time, nose 40 of member 19 progressively moves from the position represented in full lines in FIG. 1 to the position 40 represented in dot-and-dash lines. When nose 40 has reached position 40', projection 35 is about leaving projection 41. Upon further rotating counter-clockwise wheel 3 accordingly simultaneously liberates lever 21 and member 19 so that these two members are quickly moved toward their position of rest by the corresponding springs. Member 19 thus rotates coaxially to wheel 3 until the rear flank of cut-out 36 butts against projection 37. Nose 40 thus quickly moves from the position 40' to the position 40" while indexing star member moves two points forward. At the end of this quick rotary motion nose 40 is again held in a fixed position relative to wheel 3 by projection 37 thereof. Since nose 40 still extends within the path of the points of star member 10, it prevents any undue jump of this member and accordingly ensures a correct indexing thereof.

The same occurs as regards the date indexing member 20 which comes back in its rest position under the action of spring 24 as described hereabove while nose 27 also prevents an undue jump of the date indicator d.

It will be observed that the manufacture of the calendar driving mechanism improved according to the invention is simple. Moreover, the operation of this mechanism is absolutely safe; it produces a sudden and simultaneous jump of both the week day indicator and the date indicator due to projection 35 which simultaneously liberates the date indexing member 20 and the week day indexing member 19. With the improved driving mechanism disclosed reading the date and the week day indications is possible every time. Since the two indicators are indexed simultaneously, the week day indication appearing in the dial window always corresponds to the correct date indication appearing in the corresponding dial window.

it will also be observed that the improved mechanisms disclosed comprises a relatively small number of separate pieces.

Various modifications of that mechanism will eventually appear obvious to those skilled in the art. The unit represented in FIG. 2 could, accordingly, be replaced, for instance, by a usual driving wheel carrying a first pin cooperating with lever 21 and a second pin cooperating with the week day star member 10. On that way one would obtain a simpler driving mechanism which would, however, not quickly index the indicators. The fourteen-pointed star 10 could also be replaced by a usual seven-pointed star without changing any other part of the mechanism. It should, however, be noted that a l4-pointed star moving two points forward at each indexing is easier to be adjusted than a seven-pointed star. A correction of the date with respect to the week day of the date and the week day simultaneously can be carried out by means of the winding stem upon pulling the latter in hand setting position. However, the calendar correction can also be ensured by correcting devices of known type which can be mounted in the watch described. The correcting device disclosed in US. Pat. No. 3,413,800 of the Assi nee could, for instance, be resorted to.

till further changes of the improved mechanism described will appear obvious to those skilled in the art within the scope of the appended claims.

Iclaim:

1. In a date and week day indicating timepiece, a calendar driving mechanism comprising, in combination, a rotary date indicator, a rotary week day indicator, a driving wheel making 1 revolution in 24 hours and automatically indexing said indicators, a date indexing member and a week day indexing member each being movable from a rest position to a bent position and being permanently urged toward its rest position, and a detent mechanism becoming engaged in a first predetermined position of said driving wheel and being released in a further predetermined position of said driving wheel, said detent mechanism, upon being engaged, causing both said indexing members to move from their rest position toward their bent position under the control of said driving wheel until said driving wheel reaches said further predetermined position thereby liberating said indexing members simultaneously and permitting them to return in rest position while indexing said indicators in unison, one of said indexing members being mounted for rotary motion coaxially to said driving wheel, a first spring means being bent between said driving wheel and said one indexing member, the other one of said indexing members consisting of a rocking lever being mounted at the side of said driving wheel and set under the action of a second spring means.

2. The calendar driving mechanism of claim 1, further comprising coupling means provided between said one indexing member and said driving wheel, said coupling means having a free play permitting said one indexing member to move relative to said driving wheel from its rest position into its bent position upon bending said first spring means.

3. In the calendar driving mechanism of claim 1, said detent mechanism having a first nose being provided on said one indexing member and moving along a predetermined path, and a secondnose being provided on said other indexing member and extending in said predetermined path.

4. 1n the calendar driving mechanism of claim 1, said one indexing member indexing said week day indicator, said week day indicator including a star member and said one indexing member comprising a radially extending finger engaging said star member for indexing said week day indicator.

5. In the calendar driving mechanism of claim 4, said star member comprising fourteen points and said one indexing member successively engaging every other point and moving said star member every time two points forward. 

1. In a date and week day indicating timepiece, a calendar driving mechanism comprising, in combination, a rotary date indicator, a rotary week day indicator, a driving wheel making 1 revolution in 24 hours and automatically indexing said indicators, a date indexing member and a week day indexing member each being movable from a rest position to a bent position and being permanently urged toward its rest position, and a detent mechanism becoming engaged in a first predetermined position of said driving wheel and being released in a further predetermined position of said driving wheel, said detent mechanism, upon being engaged, causing both said indexing members to move from their rest position toward their bent position under the control of said driving wheel until said driving wheel reaches said further predetermined position thereby liberating said indexing members simultaneously and permitting them to return in rest position while indexing said indicators in unison, one of said indexing members being mounted for rotary motion coaxially to said driving wheel, a first spring means being bent between said driving wheel and said one indexing member, the other one of said indexing members consisting of a rocking lever being mounted at the side of said driving wheel and set under the action of a second spring means.
 2. The calendar driving mechanism of claim 1, further comprising coupling means provided between said one indexing member and said driving wheel, said coupling means having a free play permitting said one indexing member to move relative to said driving wheel from its rest position into its bent position upon bending said first spring means.
 3. In the calendar driving mechanism of claim 1, said detent mechanism having a first nose being provided on said one indexing member and moving along a predetermined path, and a second nose being provided on said other indexing member and extending in said predetermined path.
 4. In the calendar driving mechanism of claim 1, said one indexing member indexing said week day indicator, said week day indicator including a star member and said one indexing member comprising a radially extending finger engaging said star member for indexing said week day indicator.
 5. In the calendar driving mechanism of claim 4, said star member comprising fourteen points and said one indexing member successively engaging every other point and moving said star member every time two points forward. 